It is somewhat ironic that a large number of people will seemingly recognise the name of Lethe without really being able to recall what it means or stands for. It is like something that is at the back of their mind, which they are struggling to remember, the irony being that the River Lethe was the river of forgetfulness within the underworld domain of Hades.

One of the five or six rivers of Hades, Lethe is perhaps not as famous as the Styx, but played an important role in the afterlife of the Ancient Greeks. The other rivers of the Greek underworld were Acheron, Cocytus, and Phlegethon, whilst some sources also add the Mnemosyne. The River Lethe is also called the Ameles Potamos in other sources.

The River Lethe ran through the Plain of Lethe, and was said to spring from the Cave of Hypnos, or Sleep. Those newly dead who drank of it upon their arrival in Hades would immediately and forever forget about their lives and their deaths.

The role of the Lethe is not exactly clear as not everyone who had died would take a drink from the river, the heroes who resided in the Elysian Fields certainly didn’t. Most sources pointed to the fact that it was for only those souls that were to be reincarnated were to drink from the Lethe, this was in order that they would remember nothing of their previous lives once they were introduced to their new one.

There is only one recorded story of where the Lethe failed blank the memory of those who were to be reincarnated, and that was in the case of Aethalides. Aethalides may not be a well known figure from Greek mythology, but was a member of the Argonauts, as well as the mortal son of Hermes. The role of messenger for Jason was given to him because of his power to remember everything. It was an ability that lived on in Aethalides even after his death, and despite being reincarnated first as Euphorbus, then Hermotius, Pyrrhus and Pythagorus, the possessor of Aethalides soul was able to remember the lives and knowledge that had gone before.

As with all water sources in the ancient Greek world, there was an oceanid or naiad associated with the River Lethe, and as tradition dictated she was also known as Lethe. The naiad was also linked with the acts of oblivion and forgetfulness, and some sources believe that she could induce forgetfulness without the need for a victim to drink from the river. The naiad Lethe was the daughter of Eris, the Greek goddess of strife, making her the sibling of Ponos, Horcus, Limos and Algos, all of who were linked to discord.

As previously mentioned some ancient Greek sources have added the Mnemosyne to the list of Hades’ rivers, and fits in with the common notion in Greek mythology that everything had an opposite. Therefore just as the Lethe would induce forgetfulness, drinking from the River Mnemosyne would ensure that everything was remembered. It was a belief that saw sub-religions grow up and members of these sects were told that they were to drink of the Mnemosyne rather than the Lethe so that they would be able to know everything.

Despite its fame being surpassed by the River Styx, the River Lethe was often used as a description of Hades as a whole. Hades itself was not hell in the modern sense and could be a place of rejoicing but could also be somewhere were all past ills could be forgotten.